Laser treatment of benign prostatic hyperplasia (BPH) is a developing, minimally invasive method. The method relies on the conversion of light absorbed by the tissue into heat, inducing irreversible tissue alterations.
Various treatment strategies exist. One of the most frequently employed technique is visual laser ablation of the prostate (VLAP), using the Nd:YAG laser and side-firing fibres for transurethral irradiation. A common procedure is to irradiate at 60 W for 60 s in four quadrants, producing rapid and selective coagulation of the hyperplastic tissue. Current side-firing fibres placed in the urethra irradiates a spot approximately 2 mm in diameter, resulting in limited lateral extension of the coagulated volume.
A drawback in this procedure is that repeated irradiation steps are required for producing coalescing lesions. The efficient heating from a concentrated beam will require an effective monitoring of the temperature development in the tissue, so as to avoid unwanted damages of other parts of the surrounding tissues. It is difficult to achieve this type of monitoring and the patient would be exposed to a higher risk than if another type of heating is used. Due to the fact that very high energies are absorbed in a small local spot, the patient needs in most cases general or spinal anesthesia.
An object of the present invention is to avoid the above specified drawback. A further object is to provide a device which at a low risk for the patient facilitates an effective treatment. These objects are achieved by a device as claimed in the independent claim.
The device according to the invention will make it possible to treat the entire length of the prostatic urethra after positioning a light probe in one single location. In a preferred embodiment this could be achieved by using a laser probe with an illumination field in the shape of a rectangular bar instead of a circular spot.
In a preferred embodiment the device is formed as a side-firing laser catheter. It will fulfill the following requirements: lateral irradiation in order to heat the lateral prostatic lobes selectively, extended length of laser emission in order to treat a large portion of the prostatic urethra in a single session, and minimized loss of laser light for good light economy. Other right sources may also be used.
Further objects and advantages of the invention are shown in the description below and in the accompanying drawings and dependent claims.